The Universities of Columbia, Arizona State, and Michigan along with CalTech have joined together to create a nanobot that is only 4 nanometers wide and successfully traversed a distance of 100 nanometers (50 steps). The four-legged robot can turn, move, start and stop and was built out from a protein called streptavidin that as four symmetrically placed binding sites or "pockets" for attaching legs made of biotin. The robot's instructions come from outside its body since it is too small to contain any processing elements. They created a track for the robot to follow from strands of DNA and the molecules that make up the track contains the instructions the nanobot "reads", that tell the robot what to do.